


The Common Denominator

by Rrrowr



Category: Supernatural
Genre: Alternate Universe - Aliens, First Kiss, Intimacy, M/M, Miscommunication, Telepathy, The Great Blind Sassy Exchange, pre-polyamory
Language: English
Status: Completed
Published: 2012-04-21
Updated: 2012-04-21
Packaged: 2017-11-04 01:35:04
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 12,464
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/388199
Author URL: https://archiveofourown.org/users/Rrrowr/pseuds/Rrrowr
Summary: <blockquote class="userstuff">
              <p>Alien!AU. Castiel is an envoy from another world with the ability to learn everything about a person through touch. Sam is his guide. Together, they explore different aspects of human life -- from the concept of ownership to the great pancakes vs waffles debate, to the various ways that people can care for each other.</p>
            </blockquote>





	The Common Denominator

**Author's Note:**

> Written for [Zee](luciferesque.tumblr.com) for the [The Great Blind Sassy Exchange](http://sastielweek.tumblr.com/post/19848243113)

This is how the day starts — with Sam stumbling out of his apartment, late already and rushing it to the embassy because today is the big day. The day where the Angels finally agree to send an envoy between their planets. The Ambassador will be busy with the Angels' military leader, Michael, but Sam gets the other one — whoever it is. Sam hasn't met them yet, but he can't help being excited about it. An Angel — all to himself, to watch learn and soak up information like a sponge. Dean's been making bets that it's going to be Anael that they choose because she's curious about everything and eager, but Sam doesn't think so because she's a soldier first and under Michael's jurisdiction to boot. The Angels will probably send someone … he doesn't like thinking in terms of expendable, but whoever they send is likely to be less critical to the safety of their home planet and more likely to be able to hold their own.

In any case, it doesn't matter who bet what anymore because they'll find out soon enough, and even though Sam shows up late and has to brush pieces of granola bar off his shirt, he's still there before the Angels are, left to mill around with his teammates and the Ambassador for a few minutes before the room they're in splits open at the far end. It's blue light and song — the sweet trill of notes fluttering like birds' wings around the faint taps of two sets of feet finding ground. 

The light is so bright that everyone has to turn away to avoid being blinded — so bright that it should be frightening, yet the emotion that stirs Sam's heart to pounding isn't fear but excitement. Sam will never not be amazed and slightly intimidated by this show of technology and power. Spaceships, sure. Basic superpowers like telekinesis and pyrokinesis, sure — Sam's got the first up his sleeve as it is. But instantaneous interplanetary travel through light and the Angels' species-wide gift of psychometry? It makes dealing with the Angels as a whole rather difficult because they have no need for any technology that Earth might give them; their interests lie with only one thing — cultural knowledge — and it's the reason why Sam's here today, as mediator between the Angelic envoy and Mankind.

Michael is the one that breaks forth from the light first. He seems slight, but he carries himself as if he were bigger, broader — as if his body does not quite suit him or as if he's used to wearing something heavier, like armor. He's dark haired and followed by a companion, also with dark hair and a slight build, and together, they stride forward one after the other until the blue light snaps away behind them as if it had never been. 

Ambassador Coulson — good guy, nerves of steel — hesitates a fraction of a second before he takes the hand that Michael holds out and no wonder. Secrets are the hazardous byproducts of his position, and one touch from an Angel reveals an awful lot in just plain factual information. Talk is brief with Angels, always. It can't help but be brief. There isn't any need for explanations because a single handshake can tell them everything that you already have planned for the day. As soon as Ambassador Coulson releases Michael's hand, Michael turns to his companion and touches his shoulder, passing on the information silently as his other hand gestures toward Sam and the rest of his team.

"This is Castiel," Michael says. "We will be leaving him with you to gather information. He will be the reservoir for our knowledge on your kind."

Then, the Ambassador is off to the side with Michael, and it's Castiel who takes up the whole of Sam's attention as he turns first to Dean. Their handshake is brief, barely there, and Dean withdraws as quickly as he can — scared, Sam thinks, that Castiel will see too much of all the thoughts and feelings he holds close to his chest — and Castiel follows his example with an uncomfortably furrowed brow. Castiel makes his way through Bobby, who is just as antsy about being known as Dean is, and Ellen, who is guarded too but bold about it. By the time Castiel makes his way to Sam, he looks very shaky and uncertain about the task he's been set with and his welcome. Sam feels a surge of sympathy. He knows what that's like — even with Dean... _especially_ with Dean — because of his super-freaky mutant powers and humans not being sure that Sam's one of them anymore because he can throw things across the room with his mind. He gets it, though he isn't sure that Castiel gets it, and so when Sam grasps his hand, he tries to project as friendly and calm an atmosphere as possible.

Next thing Sam knows, not only does he have Castiel's hand in his, but Castiel's other hand is reaching to grasp his elbow and then his shoulder and then his neck. Castiel steps in close like he's greedy to feel how happy Sam is that he's here. It's weird, to be honest, and Castiel's presence is like a faint tingle along his spine, slipping through his thoughts like a whisper — polite and unobtrusive; perhaps a bit sweet. 

For anyone else, it might feel like an invasion to know that the Angel's reading everything he's thinking and everything he's feeling, but for Sam... God he's just curious. Can't fault him for that, can you? He's curious as all hell and he watches Castiel read him with a sort of morbid fascination, wanting to see Castiel react to his thoughts — if he reacts at all. 

Castiel's lashes flutter and his hand shifts until it's not just fingers against Sam's spine but the whole, heavy palm resting there like he might drag Sam down at any moment for a kiss. He says, "Oh," like the things he reads in Sam's brain are a surprise. Then he says, "You are quite pleasant," in a distantly observing tone, "and curious. I like curious things."

Sam gets distracted for a moment by the Ambassador asking awkwardly how long they can expect Castiel to be staying on Earth, and Michael's reply is a disconcerting, "Indefinitely, or until such a time as he has a full grasp on what it means to be human." Which — wow, okay, that might be a damn long time, and Sam wonders how Castiel feels about that — if he's excited about exploring a new culture or dreading the prospect of an overlong visit on a world that's so vastly different from his own. Maybe he doesn't feel any of these things because these emotions are purely human — attachment and sentimentality over people and places and objects and—

Castiel's fingers grasp ever so lightly at Sam's nape, tugging, and Sam turns his attention back to Castiel in time to feel a gasp of breath and the press of dry lips against his cheek. Then Castiel's voice: "You are very kind, Sam Winchester. My thanks."

So that's that. Castiel withdraws by inches, fingers daintily sliding away from Sam's neck and from his hand until there's space enough between them for another person at least. If there was ever clinical detachment in his expression, Sam is at a loss to see it now as Castiel says, "It is a pleasure to know you."

Sam's sort of dazed in the wake of the whole moment, helplessly watching after Castiel as Michael explains that he'll be leaving as soon as possible, and he's too busy sort of soaking in the fact that he can still feel a tingle in his skin where Castiel touched him to realize that the blinding blue light he's turning away from means that Michael has left and that Castiel is, officially, under his charge. 

That by itself is sort of mind boggling, despite the foreknowledge of that arrangement. Of course, he's glad that Castiel seems to like him — flattered really because everyone seems to be under the assumption that Sam's already being favored over the rest of the team — but the idea that this assignment might take the rest of his life and then some is pretty overwhelming. He expected a few days or a month at the most, like Castiel was some study abroad student getting a basic grasp of life in a new place. He'd been prepared for that — had Castiel already set up with a furnished apartment and everything just a couple doors down from him, as a matter of fact — but understanding what it means to be human? Hell, most _humans_ didn't figure that out within their lifetime and they didn't have the benefit of the extraordinarily long lives of Angels. 

If Castiel is at all troubled at the prospect of his task, it doesn't seem to show — not when Sam drives him to the apartment complex or gets the keys for the apartment from the clerk, and not when Sam leads him into what's going to be his new home. Castiel's cool as a cucumber to be honest. Unflappable and somewhat stoic and unblinking as he takes in everything and touches _everything_. His hands ghost over the furniture in the same way that he touched the dash of Sam's car, and Sam has to wonder if Castiel can get information from objects like he can people — if he touches the wooden chairs and senses how it was built and which trees it took to put it together, if he knows the lumberjack that cut the trees and the machinery that cut the pieces and whoever it was that put the pieces together and set it here. He suspects that Castiel would answer if he asked. 

Angels don't seem to have the same scale of personal anything — not personal space, not privacy, no individual possessiveness. There are no secrets between Angels, and Sam figures that just goes hand in hand (ha ha) with their abilities. How could you conceal anything when the slightest touch revealed everything? You'd have to cut yourself off entirely from your people to get a sense of individuality, which begs the question of why Castiel's okay with being separated from the rest of his people for so long.

Sam feels the question rising in his throat, feels it filling his lungs with curiosity. He wants to know, but can't ask the question — too soon, too strange. For himself anyway, even if Castiel wouldn't mind. Hell, Castiel would probably encourage the questions, seeing as he likes curious things so much, but instead of asking, Sam casts the apartment keys toward the coffee table and heads toward the kitchen.

"I wasn't sure what you liked, so I got a bit of everything," he tells Castiel as he opens the fridge. 

Castiel drifts up behind his shoulder and peeks in at the fruit and the vegetables, the small packages of meat, and the milk. Sam kept it simple when he chose the food — didn't want anything too complicated, but also wanted to give the kitchen potential for something more. During the grand total of two meetings between Angels and Mankind, Sam never saw Angels eat, though there had been tidy banquets at both. Sam's two steps away from thinking that eating is something intimate for Angels, when Castiel plucks an apple from the shelves and steps back, turning the fruit over and over in his hands.

"You intend for me to eat this?" Castiel asks. "The seeds are poisonous."

"Well we don't eat the seeds," Sam says. He shuts the fridge and turns to rummage through the drawers for a knife before taking the apple from Castiel's hands and cutting him off a thick slice. "Here."

Eyes flicking attentively between Sam's face and the apple, Castiel brings the apple piece to his mouth and cautiously bites down. He chews for a long time and swallows. "Interesting. This is a custom common to humans?"

"Yeah, I guess," Sam replies, trying to think of how to describe human eating practices and floundering. He's not exactly a sociologist here or an anthropologist. "We... um. Actually—" and then he just grabs Castiel's hand and focuses his thoughts on everything he knows about eating.

He tries not to force the information out, tries to make it a bit organized even in his own head — the science of it and the importance of getting the right amount of nutrients every day and vitamins and minerals and calories and the things he was told as a child with three square meals a day and eating your vegetables and how there's breakfast lunch and dinner but also snacks sometimes and how it was common for people to eat together in groups but not necessary because some people went off by themselves to eat and how sometimes people felt weird about eating alone, and actually really eating is a lot more complicated than he thought before and he didn't realize just how complicated it is until he was tripping out over how some food is shared religiously and how there's giving up certain foods for Lent and how food is the way people meet lots of times, whether it's trading pudding for fruit roll ups in grade school or going on first dates at a restaurant, and how it was sometimes the last important thing that people did, what with the Last Supper with Christ or the last meal that a person got before execution, and God, that's pretty morbid and maybe Castiel doesn't want to know about that kind of thing or maybe he'll think it's weird or—

"Amazing," says Castiel with the softest of whispers, and that's when Sam realizes that they're close like they were at the Embassy — all in each other's space and with Castiel's fingers pressing firmly over the knobs of his spine. "You are so complex."

And that's just great, actually, Sam thinks — that Castiel isn't turned off by the way humans operate, though they eat when Angels don't and they sleep when Angels don't and they do all kinds of things differently. Except maybe that's the point and why Castiel was chosen to be the envoy. Because he's curious and he likes curious things and he likes knowledge and everyone would know that and so of course Castiel would be the best choice to send. 

"Good," Sam whispers. "Good, I'm glad."

Somehow, he's disinclined to make Castiel step back, though he's long stopped thinking about eating and how complicated it is when he really started examining it. He's not thinking about anything in particular, certainly nothing that'd be of cultural value like religion or traditions or daily routines or whatever. He's just standing here with an apple in his hands and an Angel's fingers on his neck and an Angel's hand in his, and it feels sweet and quiet and close and intimate and way more than he anticipated back when Castiel was just a nameless envoy. That's okay. That's good. It's positive, whatever it is, and maybe it's one of the reasons why Castiel is cool with being away from his world — because he's not exactly separate like this. It might be awkward in these first few days, but he'll pick up stuff on how to behave and how to speak. In a few weeks, a few months, Castiel might not seem all that different from anyone else Sam meets.

That makes Sam take a deep breath. He's been worried about screwing this up already because he's so not an expert on what it means to be human. He's not what Castiel would need, but that doesn't seem to matter because Castiel's just fine, no matter who he's with and that's—

"Good," he says — again — and sighs, relaxing and opening the eyes he hadn't realized he closed. 

Castiel's watching him with blue eyes that are blown nearly black, and he quirks his head to the side as he slowly slides away from Sam and takes the knife and apple with him. "We have done enough for today. You have given me much to absorb. You should rest. And eat," Castiel says as he carefully cuts away a thick slice of apple and puts it in Sam's palm as if it is a gift. "I will want to learn more tomorrow."

"Right, tomorrow," Sam says as he backs toward the door. Castiel follows him, smiling pleasantly — innocently — and one last time for the day, Sam touches him. He takes his hand and puts it against the lock on the door, asking for Castiel to be safe without saying anything. "Tomorrow. First thing in the morning."

*

The next day comes too soon, with yesterday feeling much like a dream. Sam goes through his morning routine knowing that he's getting ready to see Castiel, but cannot shake the feeling that the Angel was, in fact, merely a concoction of his imagination. It doesn't help, of course, that no one answers the door when Sam knocks. He waits for one minute and knocks again, ignoring the stare of one of his neighbors as they pass him in the corridor — but there's no response. Surely, Sam thinks, Castiel would come investigate a new sound out of sheer curiosity even if he doesn't understand what it means. 

Unless he's hurt, his paranoid mind suggests. 

So Sam tries the door, and he doesn't have to force the lock. The door opens to him without any trouble, and as he crosses the threshold, the apartment beyond is absolutely silent. Fretting thoroughly, Sam quickly moves into the deeper rooms, searching for some sign that Castiel is around or fought kidnappers or _something_. He's about to pull out his cell phone and call the cops — and report what? Missing person? Please look for young man in early thirties, in a suit and tan coat, who is touching everything — responds to Castiel and means no harm? That'll go over swell, Sam bets.

He thinks about sitting and waiting for Castiel to come back (if he comes back), but remembers that Castiel needs neither sleep nor food. It would be possible in theory for him to wander for days without ever needing to return to the apartment (if he could return). Still, Sam doesn't feel comfortable just leaving the apartment unlocked and empty on the chance that he'll be able to find Castiel on his own. Instead, he cooks and hopes and leaves his phone sitting out on the counter with the ringer turned all the way up and his email alerts on, just in case his superiors contact him to say that they've got a John Doe matching Castiel's description and oh, by the way, you are totally fired from doing anything again ever because you are a failure at responsibility. He's worked his emotions up to a frenzy and has almost finished with a chicken and rice stir fry when the doorknob jiggles—

—and jiggles again because right, Sam totally locked it, and the one person in the world who wouldn't bother knocking is the same person who wouldn't understand why the latch didn't just give away. 

Sam dives for the door at once, opening it to Castiel's minutely surprised face. "Oh, thank god, you're okay," he says, though that is perhaps a phrase spoken too soon.

Castiel's still wearing the same business-like attire that he'd arrived in — a suit that's fitted to him and a coat that's definitely not — but it's all rumpled and somewhat stained. His hair, too, is standing more on end than it was the day before. When Sam steps back to give him room to enter, Castiel does so without hesitation and goes straight to the coffee table, pulling things out of his pockets — mints, business cards, the crumbled remains of a food sample, a folded flyer for a local band, and a half dozen coins (three of which are pennies). 

"Hello, Sam," Castiel says as he starts pushing the items around on the table until they're in a neat row.

It's as if he can't tell that Sam's just spent the last ten, twenty minutes having a near panic attack. Perhaps he can't. Sam stares at him from the door as Castiel finally looks up from his cache of items, sniffing the air and then drifting toward the kitchen. He glances at Sam briefly, but ultimately focuses on touching the items that have been brought out of the cabinets and fridge — the small assortment of spices, the measuring cups, the spatula... Each touch is increasingly tentative, yet he returns to some spots again and again — the handle of the still-hot pan, the knob that Sam only just had the presence of mind to turn before he answered the door — and Castiel bites his lip.

"Sam, you—" Castiel pauses, troubled, and then he pulls away from the stove entirely, looking at his palms as if he doesn't understand what he's just read. "Worry?"

Sam shuts and locks the door before he crosses the room to reach Castiel. He grasps Castiel's hands in both of his, and that jolts a startled gasp out of both of them and maybe that was a poor decision on his part, maybe he shouldn't have done it and should let go before he gives Castiel too much. But Castiel holds him fast before he can do anything, eyes drifting closed and mouth parting as he drinks in the remaining traces of Sam's frazzled and frayed panic. 

"We're gonna have to work on some ground rules, okay?" Sam says. "I can't have you running off on your own until you're a little more..." _human_ , he doesn't say but Castiel probably hears it anyway. He barrels on: "Rule number one, you gotta lock your door. You can't just leave it open for people to come and go as they please. They could take stuff."

Again, there's a thought that rises, unbidden: _They could take you._

If Castiel thinks that thought is too forward or strange, it's another thing that Sam doesn't know and may never. Castiel merely squeezes his fingers in reassurance and tilts his head to the side as he absorbs and makes sense of what Sam is telling him (and not telling him). "I understand," he says, "but it is strange for one of the dominant species on the planet to fear itself, rather than its potential competitors."

"Yeah, strange," Sam huffs, largely grateful that Castiel accepts the rules as is. "Mankind isn't exactly peaceful."

"So I have learned," Castiel agrees and pulls one hand out from Sam's grasp to indicate a tear on the shoulder of his coat. "Today's lessons seem to be largely about material possessions and their acquisition and retention."

Sam thumbs at the tear and then squints at the curled threads at the seam — snapped, it seems, from being pulled on. "What happened? Did someone try to rob you or something?"

"Rob?" Castiel's fingers curl into Sam's. "Oh, yes. But of course, I have nothing to take. The man did not believe me and was a bit rough in his search."

Boggling at Castiel's dismissive tone at the encounter, Sam feels his worry spike again. "But you're okay?"

Castiel looks up from where he's watching Sam's thumb peel back one side of the torn sleeve. His eyes are heavy-lidded, considering. "You do not wish for me to be hurt," he says. "I am glad, but you needn't bother." His mouth spreads into a slight grin. "I may look human, but I am much stronger than this physique would imply. The man who attempted to rob me could not have harmed me." 

Sam feels a bit stupid for having worried so much. It's just as he thought when meeting Castiel — that the Angels wouldn't send someone they didn't think could protect themselves. Still, he's never seen an Angel fight or get upset or even get cut on accident, so he wonders what to trust, forgetting for the moment that his doubt is slipping across the telepathic bond between his hand and Castiel's.

Almost as soon as the doubt has occurred to Sam, he's got his face against the wall — pinned there by Castiel's weight at his back — and Castiel's voice curls from behind his ear around a hot breath. "We would not usually fight this way. Without the proper precautions, we would be overcome by the thoughts of our attackers, but with a touch, you see—" and here, Castiel covers Sam's neck with the broad flat of his palm and bears down, easing him to the ground gently with an insistent strength. "I can read whatever I like from your mind. I may also see how you plan to use your powers to fight me off, and be able to react accordingly."

Shuddering, Sam stares down at the linoleum tiling between his knees and the fine cracks between the baseboard and the wall. He feels claustrophobic — boxed in by the wall and Castiel's legs and the shadow of his coat hanging down in his periphery. The instinct to throw Castiel off of him fizzles out first, without Sam having to shove it down. Castiel's grip on the back of his neck is secure, applying a firm pressure through the length of his spine, and it isn't as if Sam couldn't wiggle free if he wished because his hands are even free or he could even shove Castiel back with his mind if he wanted — though as soon as he thinks it, it seems ludicrous to bother. He's not sure why he wants to fight in the first place—

"You see?" Castiel murmurs. "Just like that."

When Castiel lets him go, Sam lurches to the side, breathing hard as he looks up at him. "What was— That— You made it like I couldn't... _Shit_."

"I eliminated your desire to fight," Castiel explains, squatting down next to Sam. He doesn't move to touch Sam, though surely that would make it easier for them to communicate over Sam's stuttering and faltering reaction to being subdued. "We have not had to fight for many years now, but all my brothers and sisters are trained in this manner. It's preferable to using our brute strength."

Sam squints at him. "Brute strength?" he echoes.

Castiel ducks his head, looking embarrassed. "Yes," he says. "Your species is very fragile, compared to mine." Very gingerly — as gingerly as, Sam realizes, most of Castiel's touches have been — he pushes a lock of hair behind Sam's ear. "My point is that you do not have to worry for my safety or my life. I do not require your protection or help, but I... I _appreciate_ that you are willing to give it. It is a credit to the generosity of your kind."

It should be frightening that this moment is the one where it really sinks in that Sam is dealing with something that's not human — that's _alien_ , that's natural in a way that's completely unlike anything that exists on this entire planet. Just looking at Castiel, he almost wouldn't know it, except the way he perches near Sam has a way of seeming to take up more space than required — almost like he has an aura about him or something. The way he watches people — or Sam, anyway — seems to linger a little longer than necessary, and the way he walks is too much as if his body does not belong to him, and the way he touches... Sam can't pretend he doesn't know. The way Castiel touches is different — _meaningful_ — by the very nature that his hands are his way of speaking and listening.

A laugh bursts out of Sam's chest. "You're a little unreal, you know that? I mean, you don't eat, you don't sleep, and you're stronger than anything I know. I don't even want to know what it'd take to kill you, but _seriously_ , what do you need to survive? It's gotta be something basic, right?"

"Very basic," Castiel says, then grasps Sam by the arm. "Come. We will share the food you made before my return, and I will explain my kind to you. Then, you will teach me."

"About material possessions, their acquisition and retention?" Sam says because he remembers.

Castiel's smile is warm. "About everything."

*

So that's how it goes for a bit. They make some basic rules to live by and settle into a routine. Castiel comes and goes as he pleases at night, and Sam tries not to worry about what he does — if he wanders and meets people or gets in trouble — so long as he's at the apartment for breakfast the next morning. Sam gets Castiel a cheap tv and a local map. The tv gets set to one of the public channels and never gets changed, so it's always on the news by the time Sam drops in. While the tv plays, Sam cooks or brings something different for breakfast, and Castiel sits on the floor with the maps spread out on the floor in front of him. Most of the time, Sam joins Castiel while he nibbles on his serving and Sam eats heartily at his, and together, they pour over the possibilities for the day. 

The best thing about leading an alien through Earth culture is the same best thing about being the native to a tourist friend. It's like rediscovering the city through different eyes, and Castiel never wants to visit the same place twice. There's restaurants and libraries and botanical gardens and parks. There's the old theatres and the new theatres — the ballet palaces and the movie houses. Castiel asks to go to taverns and to museums and to fire departments and police departments, and while he's there, he learns everything that he can. 

Castiel learns about money and weather, price gouging and gardening, and the Dewey decimal system. He learns about groceries when Sam takes him on errands (sometimes going well out of his way so that it's a new place for both of them) and about clothing (because Sam is not going to have Cas wearing the same thing all the time). He shakes hands with the sheriff and the fire chief, cashiers and car salesmen. Nearly everyone they meet actually gets at least a brush of his fingers, and Castiel comes away with a little bit more knowledge, a little bit more culture — and seems more human because of it. 

It turns out that there hundreds of places that Sam hasn't visited in his city — places he never thinks of going to and people he never thinks of meeting — and Castiel drags him by the hand through one door and then the next. That's the most important thing right there, as a matter of fact: the hand-holding is nearly constant.

It almost gets to be that Castiel doesn't bother asking questions. Sometimes Sam is just talking, explaining this or that, and he's a big gesticulator a lot of the time — comes from being a younger brother but it also comes from being a telekinetic and from having to shape the world with his hands. Anyway it makes it hard for Castiel to catch his hand or his wrist or his arm without disrupting the conversation. So sometimes Cas takes off his shoes (which are more often just slippers now to suit the hot weather, not that Castiel would notice) and lets his toes creep up Sam's shin while his face falls into this relaxed sort of wonder as he gathers the full meaning of everything Sam is saying. Sometimes, Castiel won't bother with just that either, and he'll just — it's so embarrassing that Sam is sure that's the first thing Cas feels every time he does it — he just leans into Sam's space and slides the backs of his fingers against Sam's neck. It's so natural and so casual that Sam stops noticing after the first half dozen times that it happens and just sort of happily shivers instead.

Sam tries not to read too much into it, you know. He doesn't have Castiel's advantage here. He can't read Cas nearly at all because Castiel has adopted this sort of amalgamation of body languages and facial expressions that look sort of right, except that Castiel isn't always using them in the way they're intended. Anyway, the point is that he does try to read Castiel in the way he would another human because touching is a thing for Angels — a thing that's altogether different from the way it is with humans. For Angels, touching is every day; it's easy and uncomplicated and all of them do it from what Sam understands (at least, from the conversation that resulted from his freak out when Castiel snuck his toes up the hem of Sam's pants the first time). The intimacy that has to be achieved by humans before that sort of touch is allowed doesn't occur to Castiel, so Sam does his best to just shiver and take it. It's better that way, so that he doesn't get preoccupied with jealousy when he sees Castiel touching someone else's hands in the cereal aisle or going knuckle-to-knuckle with strangers.

It should be weird, Sam guesses, but Castiel keeps to their arrangement. He's there every morning and he's with Sam through the day. Meals take two or three times as long to eat because half the time, Sam's eating with just one hand because the other his holding Castiel's or he's having to chew very deliberately because he's trying to ignore that he can feel warm toes rubbing up and down the side of his leg, eating up information from his subconscious. 

Even if it isn't weird — which it really, totally is — the stirrings of insecurity are more than enough to make Sam feel antsy when he sees Castiel with other people. He's sure that at some point, it's going to become clear to both of them that Sam is not an expert. Sure, he can drive Castiel wherever he wants to go, and sure he hasn't exactly exhausted the internet's repertoire of recipes yet — but sooner or later, Castiel's going to ask a question that Sam won't be able to answer and then where will they be? Sam tries to focus on the fact that — while Castiel may visit with other humans, touching them and reading them — he always comes back to Sam.

In fact, there's this one time when they're at IHOP — which, yes, Sam realizes that sounds like the opening to a really, really humiliating story — but they're there for lots of reasons, like how Castiel is extra shifty and frazzled when Sam sees him after having taken the subway home and in the fifteen minutes it took him to commute during the morning rush, rubbed shoulders with fifty or sixty different people, touching the safety bars and the hundreds of thousands of people that have left behind their traces. It's also because Sam starts thinking about how he always likes waffles as a comfort food and maybe Cas will too, but he can't make waffles without a waffle maker and besides which, Castiel doesn't understand the debate between waffles and pancakes. He's really only beginning to grasp the concept that humans do a lot of things just for the pleasure of it anyway — reading and music and eating and … and other things that don't bear thinking about while Sam's holding his hand.

Anyway, they're at IHOP and Castiel's abandoned him in favor of a particularly long conversation with their waitress about how she's doing and what it's like working the night shift at a restaurant and whether there's something she loves from the menu even after so long. Castiel doesn't actually take the details of what she's saying — doesn't need them, it's too much; he gets what he needs through touch, and right now he's gently hold the hand she has covering his, with his fingers caressing the easy pulse in her wrist. The waitress allows Castiel about ten minutes' worth of conversation before she remembers that she has other tables to wait on, and he lets her go without argument, sagging back into his seat in a very human display of relief. 

A second later, one of his feet is settled against Sam's knee, and Castiel says, "I hope you know that I am grateful for you," apropos of nothing, it seems, except maybe _everything_ that Sam can't help feeling and Castiel can't help knowing. "You are open to me and—" He pauses, searchingly. "Your kind is young and cautious. There is much fear in the individual. It's what makes you lock your doors at night and distrust things with which you are unfamiliar, be it actions or other beings."

"That's normal, isn't it?" Sam asks. The fear of the unknown. When faced with a darkened room, how was one to know what it contained — if it was something good or something dangerous? "I'd think it'd be a survival instinct."

Castiel hums, hands turning Sam's palm upward and fingers tracing the thin creases that mark his individuality. "For humans, that seems to be the case. For Angels, it is different. We are a culture that thrives on knowledge. Unlike humans, we have already achieved our physical peak, so now our purpose is to achieve an enlightened state.

"When faced with a darkened room, an Angel would not be afraid but curious. We would enter without hesitation," Castiel says. He curls Sam's fingers around his own and then, remarkably — so much so that Sam feels his breath catch — he brings them to his lips. "After all, if we do not investigate, how are we to know what lies within — whether it is something good... Or something dangerous?"

Something in Sam squirms uncomfortably and at the same time, thrills. "So you're grateful for me because I'm afraid?"

Sam feels a smile stretch against his knuckles. "No," says Castiel. "I am grateful because you are not."

*

They hit one week and then one month and then two and three months without Sam noticing. They start travelling systematically farther out of town — farther than the public transportation would take them and sometimes far enough that they have to take a night at a motel so that Sam can sleep. Anyway, they start having to take Sam's car instead of walking, a fact for which Sam is extremely thankful. His legs may be _fantastic_ now but there's no way he's gonna foot it ten miles just to reach his destination, no matter how nice it is to hold Cas' hand the whole way, and that means being trapped together for increasingly long periods of time — _alone_ , with no distractions and no other people to talk to.

It's the kind of thing that tests relationships — not that having Castiel day in and day out isn't already a test as it is because he's only human and he doesn't have that thing that Castiel does, where being inside the mind of others and having them inside yours is natural and easy and expected. Even the most sociable of humans needs space now and then, which is why Sam's never thought of stopping Castiel from wandering to other people. 

Point being that they're all the entertainment the other has now, seeing as Castiel's touched the car half a bazillion times already and the radio can only do so much before they have to start talking, and talking's great — talking is _awesome_ and Sam is always on board for that, but Cas likes to hold hands while they talk because then he doesn't have to worry about missing any of the nuances and Sam doesn't have to worry about whether a slang word will be misunderstood, and well... Sam kind of needs both of those hands to drive even when he's not doing ten and two. Usually, Castiel's solution to this is easy because there's always the footsie thing that he does when hands aren't available, but now both of their feet are segregated into their own little footwells, which effectively rules out that option.

Castiel's solution to _that_ is so simple that Sam really should've seen that coming. But no. One second, Sam's edging closer to the windshield because the rain has reduced his visibility to shit, and he unlaces his fingers from Castiel's to flick the wipers on to a higher setting. The next second, Castiel's fingers are pressing into his inseam, and Sam nearly veers off the road in shock.

"Sorry," Castiel says, having pulled his hand back into his lap. "I didn't mean to startle you."

Sam takes a moment to compose himself. The rain continues pounding and the air condenses under the windshield and the wipers squeak and thump, trying to clear the water away well enough for Sam to see the car in front of him, and the radio hisses on the AM emergency station, silent for now and poignantly so, and Castiel continues to keep his hands to himself, which is actually sort of distressing — more so than having fingers suddenly lying against the inside of his thigh — and Sam shakes himself. He needs to relax.

"No, it's fine," Sam says, but Castiel doesn't move toward him. "I'm alright, Cas. You can — you can touch me."

When Castiel's hand finally moves toward him again, the fingers are splayed slightly and it moves slowly, as if Castiel wishes to broadcast his motions on the chance that approaching too abruptly might make Sam change his mind. But Sam isn't a horse, he's not some frightened animal, and Castiel said once that he was grateful that Sam was never afraid to be open with him. So he touches Castiel's hand long before it actually lands on his leg, covers it with his own from wrist to fingertips, and presses it firmly against his jeans. It feels bizarrely as if he's guiding Castiel through it, like he's showing Cas how to touch him as if they were something more than friends, and that makes him feel both uncomfortable and guiltily good.

"I didn't realize that there were stages of acceptable touching with humans," says Castiel.

Sam feels Castiel's fingers stretch out under his palm before he — very deliberately — squeezes. He stretches his leg as much as he can without pressing on the accelerator and leans back into his seat with deep, steadying breath. He leaves Castiel's hand where it is and grabs the wheel at ten and two, concentrating on the road and the light traffic and how it's getting kind of late and the exit for the hotel should be any mile now and not about how he can hear Castiel breathing harshly in the passenger seat. He absolutely doesn't react when Castiel's hand slips higher by a fraction of an inch and squeezes again — as if he's trying to pry Sam's thoughts right out of his skin, right out of his heart. As if his fingers aren't side by side with the evidence of everything Sam is thinking right now.

He tries his damnedest to control his thoughts. It's a thing he's always kind of done with Cas — making sure that his thoughts remain on topic and organized so that they can be better absorbed, and he isn't even sure if that makes a difference, to be honest, but it means steering clear of things like this that are instinctive and reactionary. It's never been like this though — under duress, maybe (he thinks slightly hysterically) and without much preparation. Because Castiel can't have originally intended to make Sam think about the last time he was touched like this (which frankly, it's been entirely too long), but there's no doubt in Sam's mind that he certainly means it now. 

Despite how awkwardly vulnerable he feels, every press of Castiel's fingers — along with every hitched breath and rub of his thumb over Sam's leg — elicits a memory that's visceral and indistinct. There are no facts to be told here, no precision. Every thought is there and then gone again, chaotic in a haze of uncertain arousal. Sam feels as if he's been reduced, absolutely and suddenly, to his base instincts — to the rapid beat of his heart and the flush of his skin, to his breath and his nerves. He's jittery now, aching for touch, and Castiel obliges him with another squeeze around his thigh and Sam's fingers tighten around the steering wheel as he grits out, " _Cas_."

Castiel just hums, low like he would if Sam had his hands on him right now instead of just his thoughts. There's a wet sound, and Sam peeks at him out of the corner of his eye — just in time to see Castiel's pink tongue catch at the corner of his mouth. Then Castiel sighs, shuddering, and his fingers curl around the seam of Sam's pants so hard that he's sure he feels the bite of nails through the denim. 

Sam clears his throat. It feels dry, like he's been gasping and hasn't realized it, and he chews on his lip for a second before saying: "Cas?"

In his periphery, Castiel blinks heavily and replies: "Concentrate on the road, Sam."

*

The rain doesn't let up at all in the time it takes them to get to the hotel, and when they arrive, the parking lot is crowded with others that have stopped to let the storm pass. Sam grabs their overnight duffel bag and then Castiel's hand so that they can run through the rain together. When they get to the lobby, they're both drenched and shivering as they shake off the excess water, and when Sam turns to look at him — hair dripping and limp and dark like a thoroughly wet pup — a laugh burbles out of Castiel suddenly. 

Sam stops just to look at him — at the way his face lights up and the way his mouth spreads open and his eyes wrinkle at the corners. Castiel is unabashed about his own delight, doesn't try to hide it or smother it back into silence. He laughs as if only Sam can hear him and squeezes Sam's hand as if he'd like to share the feeling — and in that moment, Sam wants nothing more than to kiss him, to feel that happiness against his lips.

Castiel's laughter quiets without dimming, and he sways toward Sam, still smiling and head cocked to the side — expectant.

"The room," Sam blurts, all nerves as he pushes his wet hair back from his face. "I'll just — I'll get our room and then—"

Then what? Sam doesn't even entertain specific plans in his thoughts, but the want simmers under his skin regardless and plain as day to Castiel. Checking into the hotel is practically a blur. He knows everything that he does — giving over his credit card and getting the room keys and making small talk with the clerk — but his thoughts are on Castiel. Sam keeps glancing back at him over his shoulder, finding him in the thin crowd and holding on to their luggage. 

He looks small and still among all those people, hair all spiked up from where he's rubbed away the rain and his coat hanging heavy and damp around his shoulders. Once, it might have seemed like an unnatural peace that threw the truth of Castiel's alienness into sharp relief, but now Sam sees the things that make Castiel seem more human — the shift of his feet to keep comfortable as he waits, the fidget of his fingers around the duffel bag's handle, the way that his eyes follow everyone that passes him and still return to Sam. It makes him nervous to be watched like that, like Castiel is picking him apart and examining him from across the room, and it's no help to remember that they've been each other's company for months now and that Castiel's probably learned body language well enough that he can read Sam just as well at a distance as he can when they're touching.

Sam's earlier want had been unfocused. For all that it was Castiel's hand crawling up his thigh with a purpose, it hadn't mattered that it was Castiel at all, but now—

God, he just can't stop _thinking_ about how he only ever gets one bed because he's the only one that still sleeps between them and how it felt to have Castiel touching him on the drive here and how he didn't run from Sam's thoughts even when they became more personal and how he can still feel the shiver in his nerves from the scrape of Castiel's nails and how he may not have said so explicitly — may not have even thought so — but there had been a promise in his words.

They hold hands again on the way to the hotel room — with Sam carrying the duffel bag over one shoulder and Castiel sliding so close that they bump up against each other with every other step — and Sam fights down the rising sense of anticipation and fear tightening around his throat. Castiel covers Sam's hand with both of his and squeezes — which just serves as a reminder, really — and then rubs over Sam's wrist soothingly.

"Don't be afraid," he says. "I'm the one exploring the unknown, not you."

Yet when they're in their room and the door is shut behind them, it's Castiel who has to make Sam set their luggage aside, and it's Castiel who steps close and tucks his cold hands into the crooks of Sam's elbows as he rises onto his toes. And while the world around them roars with the storm, it's Sam who trembles, afraid and uncertain, as their lips press together in a way that is not quite matching, not quite what Sam had envisioned. It's a kiss without heat, without passion, without either of them fighting for it through their rain-soaked chill. Castiel does not push for more than that gentle touch though, and Sam feels him exhale — softly frustrated — before he begins to ease away.

The imperfection of the moment loosens the tension around Sam's chest. It twines out of Sam in a gossamer thread of longing, and Castiel has barely put his feet back under him before Sam is bending toward him, cupping his face and tilting him up for a kiss as it should have been — as it _is_ now that Sam is showing him, teaching him, pouring into Castiel's mouth all the affection and still-blossoming desire that's been hoarded away inside him for god knows how long, if maybe it's just been these last few weeks or this whole time, from the moment he saw Castiel following Michael out of a backdrop of blue light. 

It's all revealed now and there's no taking it back, and it's as if a dam has broken, letting everything spill out and rush forward. Castiel makes a noise against Sam's mouth — sharp, shocked. Then one of his hands is at Sam's shoulders, slipping easily over the back of his neck, and an instinctive burst of adrenaline spikes through Sam's gut, reminding him of how easily Castiel had taken him down months ago and how easily Castiel could do the same now. It makes Sam kiss harder — makes him scoop Castiel closer as heat and desire hum dizzyingly through his whole body — and gone is the crisp chill from before. In its place is heat and heat and more heat, and when Sam gasps and digs his fingers into the high arches of Castiel's hips, Castiel knots his fingers in his wet hair and makes no indication that he intends to let go any time soon.

It feels — It's different. Sam, he— He knows he's being read. He knows that every flickering observation he notes is being picked up — whether it's the dryness of Castiel's lips or the sweaty heat of his palms or the wet sounds of their mouths meeting and parting and meeting again, whether it's the hot rush of blood in his throat or the very primal urge to duck under Castiel's jaw and taste and bite and suck the lingering rain right off his skin or the slightly darker wants that he so rarely entertains—

Fuck, Sam doesn't care that Castiel can see it all. He _wants_ Cas to see. He wants him to know. He wants Castiel to delve inside him and take — just take it, take _everything._

Castiel shivers and his nails scratch encouragingly against Sam's scalp. He pulls. He gasps. He whimpers Sam's name for no other reason, it seems, than to indicate that he wants the same things, and it is the most human and most wonderful sound Sam has ever heard.

Then Sam's phone rings so shrilly that they both jerk away from each other.

"Sorry," Sam murmurs, fumbling through his pockets and then checking the caller ID before he answers. "Hey, Dean," he says and reaches for Castiel's hand.

Dean's just calling to check up on him because of the weather and knowing that Sam and Castiel are supposed to be out in this direction — wants to make sure they're okay. It's sweet. Sam appreciates it and tells Dean so as he watches Castiel lean against the nearest wall. Sam follows — can't not follow even with his brother's voice in his ear — and kisses his brow, his cheek, his mouth again between reassurances that yes, Dean, they got to the hotel safely and they've checked in for the night and they'll be back by tomorrow afternoon.

Castiel turns into every touch like he's seeking it out and it's adorable, honestly — all sleepy eyed and soft, as if he hadn't been clawing at Sam three minutes ago. Already reminiscing about long moments lost to passion, Sam thumbs at the swell of Castiel's lower lip and follows it with his mouth, nosing close and then withdrawing to make his goodbyes to Dean and guides his phone next to the television across the room.

"Is this how it always is?" Castiel asks when Sam turns back to him. He comes willingly, too, when Sam opens his arms for an embrace. He breathes deep and seems to sink closer on the exhale — snuggling in, soaking up the comfort.

Sam hums, and though his hair is dripping cold against the back of his neck, he feels warm where it counts. "Is this how what is?"

"Passion. Affection. And what was it you thought... ah, more than friends," Castiel says. He lifts one of Sam's hands from his waist and splays out the fingers against his own. "Connecting more deeply with others. Is it always done in this manner? So physically — without thought or logic and full of just feeling and _emotion_?"

Sighing as he thinks, Sam speaks, though he knows that Castiel will find the details in his thoughts anyway. "No," is his answer. "Becoming more than friends isn't always like this. It depends on the people involved and their preferences."

"Hmm, varied sexualities." Castiel laces his fingers with Sam's. "That does make it more complicated — more individual. Should we have spoken beforehand?" Sam shrugs, but then wiggles their joined hands. Castiel huffs a laugh. "Point taken."

So with that, Castiel nuzzles up under Sam's chin and lets go of his hand so that he can turn Sam toward him, and they kiss like that — differently from the first time and softer than the second, but just as wonderful and somehow, romantic enough to make Sam's heart flutter. Castiel's knuckles smooth against his jaw as they part, and his lashes dip low as he licks his lips. Sam imagines that he's tasting something — not just the salt of skin but also Sam's thoughts, his emotions — and suddenly he wants to kiss Cas again and again and again, forever perhaps or as long as he can.

Castiel leans in again for a peck, humming happily, and says, "You should sleep. It's a long drive back."

*

Sam wakes up late and Castiel is gone.

His first thought is panic and then wonder and he looks around him sleepily, thinking that perhaps the nearly-silent fear that last night was the clincher — that Sam would open his eyes to an empty room and an empty life and an Angel that left him behind as easily as he'd arrived. But then there's a soft noise from the bathroom and a knock at the hotel door all at the same time, and Sam has only managed to sit up before Castiel swings out to open the door for — of all things — room service.

"What's this?" Sam asks.

"Breakfast in bed," Castiel says, and he lifts the tray from the cart and gingerly sets it across Sam's lap before climbing onto the opposite side.

Sam lifts the cover off of one plate and finds an omelette, still steaming and filled with vegetables, and then lifts the cover off the other and finds a bowl of cut fruit and thick cream. "I don't remember you learning about this, Cas."

"You were asleep," says Cas as he picks a piece of orange out of the bowl with a fork and dips it in the cream. "The television here plays movies."

Nodding, Sam starts in on the omelette. "I thought we talked about how movies aren't always accurate portrayals of human life."

Castiel smiles. "We did, but that doesn't mean that they must be wholly inaccurate."

Sam doesn't have to search through his memories of the half dozen morning-afters that he's had to know that this one is the easiest. He doesn't feel the need to explain anything and when he feels the urge to kiss Castiel again, he doesn't have to say it. Cas just slips close, warm and sweet and tasting of cream and fruit, and does so. There's no pressure. There's no second guessing. Castiel understands everything.

So he's basically worry-free from that point on — through the drive home on still-slick roads that takes them by a completely different route and through the next few days even, when Castiel starts greeting him with a kiss first before reaching for Sam's hand. He tries not to let the way Cas kisses get to his head, even when each kiss is lingering and delightful — especially when he starts to think that Castiel might actually like kissing an awful lot and not just because it's an openly intimate way to slip into his mind. 

Though Castiel never says one way or the other if he's right, Sam is sure that he wouldn't keep kissing if Sam was wrong because Cas doesn't have that human need to please others — doesn't have that sense for peer pressure. He's only got curiosity and the drive to satisfy it. So Sam goes on not worrying and goes on with their life-plus-kissing-which-is-awesome and he goes back to his own apartment to sleep.

Sam's pretty sure that Castiel still wanders at night while Sam's gone. Pretty sure anyway, though he wonders if Castiel bothers now that the immediate cityscape has been thoroughly explored or if he figures that, since he's seen it all once, there's no reason to go through a second or third time. Cas probably bothers, whether he thinks it's worth it or not. He's a kind of scientist at heart — exploratory, of course, but considering the task of understanding the human condition, Cas would probably try to meet as many humans as he could, touching each of them and seeing what similarities and differences lay between them all. 

He's in the middle of this train of thought while he's locking up his apartment before heading over to Cas' place. It's only a few doors down. Sam just has to skip a bit down the hall — which he has totally, _never_ ever, done by the way — and so he's in prime position to notice when Castiel's door opens and someone comes out. A girl someone that is not Castiel. A girl someone with her hair twisted up in a clip and a shirt that's knotted under her breasts and a short skirt that leads straight into goddamn fishnet stockings and heels that could kill a person. 

She couldn't— 

Sam shakes his head.

No way, she couldn't possibly be — and yet, he sees how shabby her clothes are, like they're washed and worn frequently. There's tears on the outsides of her stockings and the shoes have scuff marks all around the sole and her nail polish and lipstick — which Sam only notices because she cups Castiel's face and kisses him deeply — are cherry candy red. When she pulls back from Cas, she's got his lower lip between her teeth, and she says her goodbye with a strong hint of suggestiveness and Jesus Christ, she's caught him staring, but doesn't seem to mind. 

She smiles at Sam too. Says: "Mornin', sugar," and sweeps past him with a rich and attractive laugh and a pinch to his ass that makes him drop his keys, and he stammers out, "M-morning," like he totally hasn't just seen a hooker walk out of Castiel's apartment and like he totally isn't continuing to watch her as she swaggers happily toward the stairs. 

Castiel is leaning on the door frame when Sam finally gets the presence of mind to whirl around and get a good look at him, and Sam is walking toward him before he remembers to call his keys from the ground. They hit his palm with a ringing slap that hurts and he snaps out, "What the hell was that?" even as Castiel's reaching to kiss him as if it were any other morning — as if he hasn't just finished probably spending the whole night touching someone else, kissing someone else, doing things that Sam hasn't dared hope for yet.

When Castiel kisses him, he smells like cherries and his lips are slickly wet from the woman's lip gloss and Sam can't help the sharp dislike that snarls out of his gut. And he knows — he _knows_ that he probably doesn't have a right to complain or make demands. Castiel never made any promises, and it's not they've ever talked about how relationships work at this level, let alone how it might work for them, and Sam's just now realizing that might've been a mistake, considering the way he's pulling away from Castiel's plying fingers instead of giving into them like he normally would be.

"I've upset you," Castiel says and he's straining toward Sam, covering the hand Sam's braced against his chest with his own and feeling his way through the emotion that Sam's never had to display before. "You feel betrayed. Because of the woman."

Sam doesn't bother explaining his feelings. Castiel will read them more truly than his words could ever convey, and God help him, Sam is vibrating with an impotent kind of emotion — wanting to be angry but feeling as if it's unjustified. So, he says, "Who was she?" like he doesn't know, and also: "Why did you—?" though he can't finish that question quite.

"Her name is Yasmine and she solicits individuals for sex," Castiel answers — doesn't seem to care that he's saying these things out in the open, but Sam is suddenly massively aware of it, made uncomfortable by it — and Castiel carefully pulls him into the apartment, closes the door behind them and locks it just as Sam taught him that first day. "As for why, I was curious, and you did not seem to be interested in progressing beyond kissing."

"So you just—" Sam slumps against the bar that partitions the kitchen from the rest of the apartment, out of Castiel's reach, and absolutely does not look toward the very open door to Castiel's bedroom or the rumpled sheets. Instead he points in the general direction that Yasmine had left in. "You picked up a woman off the street and walked her back here and just—"

God, he can't even say it, so he skips right over it.

"— _all night_?"

And maybe his voice gets a little tight around the last two words, but he's feeling a little hysterical because Castiel keeps trying to touch him and he doesn't want Castiel to know that he _can_ feel this dark, ugly thing. This jealousy that is thousands of times worse than the casual rivalry he felt toward anyone that Castiel touched who wasn't Sam.

"Yes," Castiel tells him, brows furrowed tightly as Sam evades him. "Sam, I don't understand—"

Sam puts the sofa between him and Castiel, waving a dismissive hand. "No, I mean. It's fine. You have a right to do whatever you like, Cas," he says, but he doesn't mean it honestly — he doesn't _want_ Cas to go off and do whatever, when _whatever_ seems to include women named Yasmine.

Castiel frowns and says, "Clearly not," as his eyes dip toward the furniture that separates them and then he reaches out again, not to Sam this time, but to the corner of the sofa. He grabs it and pulls and the sofa moves — more than a couple inches, more than a foot, moves all the way across the room so that Castiel can stride straight toward Sam and _touch him_. "Oh." Castiel sighs, eyes closing. 

"Don't," Sam whispers, trying to squirm free of Castiel's grasp, but he can't — he's pinned again, back to the wall with Castiel's hand splayed across his chest.

"I must or I will not understand," Castiel says.

It's the frank, open way of speaking that Sam hasn't heard in months — the way Castiel spoke back in the earliest days when he was the most alien, the most Angelic. Somehow, Sam had forgotten he'd ever spoken like that. Castiel's thumb rubs at him through his shirt, and his face is tucked in and focused as he digs through the maelstrom of Sam's thoughts and Sam feels something akin to shame crawl through his skin.

Castiel whispers, "Don't be afraid," in a tone that is gentle, soothing. "Fear is what closes us off from experiences. Whatever you're trying to hide from me, do not think that I will judge you for it or turn you away. I'm here to learn and you are here to teach insofar as you are willing."

"I can't," Sam confesses. It's so hard to get rid of feelings once they've been felt — so difficult to accept that they're even there, more so when they're things like anger and jealousy.

And Castiel nods and slips one hand behind Sam's neck, lays his palm heavy and flat against the nape. "Just breathe," he instructs, "and that will make it easier for you to let me in."

So Sam breathes and he closes his eyes and he feels his knees buckle and together, he and Cas slide to to the floor and Castiel makes a sound like he's relieved about something that's been worrying him but Sam can't focus, can't think of anything now that might've worried him because even the jealousy, even the anger and guilt and sadness that's been clouding his mind seems distant and beyond Sam's concern and that's okay, that's good, that's—

"Speak," Castiel commands.

"I just—" Sam swallows. He knows that without Castiel's hand on the back of his neck, he wouldn't even know how to say this so plainly, but it's like his emotions have just swept up to the front of his mind in text that's easy for him to give voice, as if every desire to hide away has been removed. "I wanted it to be us. I wanted it to be special."

Castiel hums. "And you feel as if Yasmine's presence has disrupted that." His fingers squeeze slightly under Sam's skull. "Tell me what you mean by special."

"Special like good," Sam says, waving his hands a bit as he searches for words.

"Yasmine was good," Castiel tells him, but Sam shakes his head.

There aren't words, really, that can be used to accurately convey the full feeling of what it's like to experience something physical like sex with someone you have an emotional connection with — how it's more than just the feel and smell and taste or the shake of your limbs or that trembling climb to completion, how it's also about how all those things have meaning or memory. Because sex is good all on its own, true, but sex with someone you love and care for — which wow, Sam is just now realizing that might actually be a real possibility here — can be _transcendent_. 

And when Sam reaches that word in his mind — gets the glow in his chest that comes from intimate knowledge of what that feeling is exactly like — Castiel sucks in an audible breath and lets Sam go. For a long moment, Sam stays where Castiel leaves him, resigned to whatever decision gets made now and also relieved that everything he's thought and felt and wanted to deny is out there in the open.

"I didn't realize," Castiel says.

Sam pushes himself up, gets his legs out from under him so that he can rest against the wall and look up at Castiel's softening expression. He scoffs, not wanting to be pitied. "It's stupid, so don't — don't worry about it. You didn't have to realize."

Castiel covers Sam's hand and pets it, almost. "But I do. It's the reason I'm here — to understand wholly what it means to be human, and that includes all the good things and the bad things, the physical and the emotional. Everything. To leave anything out would be a disservice, especially when you've given such a valuable lesson today."

Squinting at Castiel doubtfully, Sam shrugs. "Not really following here."

"Strong emotional attachment and physical intimacy," Castiel explains. "For Angels, we do not require one to achieve the other. You are already aware of how easily that we touch — with much greater ease than humans. But love and sex and connection, these things are for humans as communion is for Angels. When we gather for worship. Like sex, it can be an act done alone, but it is better when we are together — when we have turned our minds toward a single purpose. It's..."

He pauses thoughtfully, then sighs.

"It's more?" Sam suggests.

"More, yes," agrees Castiel, smiling with the simple pleasure of being understood. "More in every way. But my taking communion with one set of Angels does not lessen the meaning of the communion I might take with others. Just as my being with Yasmine would not lessen the meaning of any physical intimacy I might have with you or anyone else I so choose."

"And if I didn't want you to be intimate with anyone else?" Sam asks. 

Castiel is quiet again as he thinks. "From the beginning, I have shared everything that I am with all of my brothers and sisters. If you want me to be with you at the exclusion of all else, it might be best if we don't progress any further than we have already. However, you should know that, were we to enter a physical relationship, every time I am with you, I will be _with you_. You cannot read my thoughts, but in those moments, I would only be thinking of you."

Sam thinks of how he trusted Castiel early on — how the Angel might talk with and touch others, but would always circle back to Sam eventually. It was easier then, but it could be that simple still if Sam could just let it. Even so, there's a possessiveness that he can't help. He wants Castiel to look at him and only him, and he wonders if having just a taste of possibility will be enough to sustain him. When he opens his mouth to voice it, though, it feels almost childish to claim sole possession of Castiel, a being in his own right. How long has Sam accepted him going to others? How long has he watched Castiel laugh with them? How long has Sam understood that he couldn't possible be the beginning and the end of Castiel's human experience? How long has Sam been grateful for the scraps of humanity he's seen Castiel display without once considering just how alien he still was? 

Sam's been so busy teaching Castiel about humanity that he's failed to remember the very fundamental truth of Angels. No personal space. No privacy. No individual possessiveness. When Castiel says that he shares everything with his brothers and sisters, he means it. On a world where intimacy is as natural and public as breathing, where there's no word for _secret_ or _loneliness_ — where their language references the plural except in names, all _we_ and _ours_ and _us_ — the concept of exclusivity is absolutely foreign.

"Okay," says Sam. He isn't at all sure that he's telling the truth right now, but there's a desperate part of him that wants to try — to understand Castiel as easily as he is understood. "Okay, I think... Maybe I can do that."

Smiling, Castiel leans in. "Can you?"

Sam nods — perhaps a bit frantically. "Yeah. Yeah, I can—"

Castiel kisses him then, and Sam is quick to hold fast to him, to openly feel the unfettered joy of getting everything that Castiel has to offer and giving all of himself in return. This is more than the kisses they exchanged the first time or have exchanged since, and knowing that — _feeling_ that — makes Sam shake so hard that when they part, his breath comes out with a terrified tremble.

"I can do that."

*

Epilogue:

"Is it appropriate for me to say, 'happy anniversary'?" Sam asks. "It's been a year since you got here. Would you say you've made progress on the human condition?"

On the computer, Castiel has the weather report up for the next week in a city in the neighboring state. He's standing by his suitcase, with different sets of clothes in each hand, and he ends up shoving both sets into the suitcase before he decides to answer Sam's question with a shrug.

"Your species is young and chaotic," he says. "My hypothesis this week may not be true next week. Your kind will not settle into a common purpose for many generations, I think. Often I think that I will never be able to understand what it means to be human."

Sam leans in the doorway, watching him. "You okay with that?"

Castiel zips up his suitcase and looks up at Sam with a smile. "That is the point, isn't it? The not knowing and the wonder. Beneath your belief structures and your hypotheses, the unknown remains the common denominator."

Ducking his head, Sam smiles to himself but nonetheless reaches out to hook his index finger around Castiel's pinkie. "So you're staying then? For a while?" he asks and does not bother trying to tamp down his hopes for a positive reply.

"Yes, Sam," Castiel says. "I'm staying."

**Author's Note:**

> Prompt: Meta Human!AU  
> Sam Winchester is a powerful telekinetic living in and working for a secret government agency. Castiel is a recently indoctrinated being from another plane that has the ability to learn everything about a person through one simple gesture — a kiss. The more intense and prolonged the kiss, the more information he can gather, stretching all the back into the subconscious if he so chooses.  
> Castiel gets put under Sam’s tutelage as a new agent within the organization, a position he accepted very begrudgingly. Sam is intrigued by his new partner and tries his best to teach him what he needs to know while also respecting the psychic boundaries. Castiel is not so respectful and approaches Sam with a kiss that knocks him off his feet during their introduction.  
> Take the story wherever you like.
> 
> *
> 
> Sam's telekinetic powers are present if you squint, but weren't really a big part of the fic's focus. Hope that's okay, Zee!


End file.
